Automatic regulation of reflux in fractionating towers



Nov. 12, 1929. H. w. NOEL. 1,735,470

AUTOMATIC REGULATION OF REFLUX IN 'FRACTIONATING TOWERS Filed Sept. 21, 1925 I mfsPolvsms ELEMENT TEMPERATURE 7PESPONSIVE I ELEMENT.

FIG-E Hamw M. on. avwewcoz 32, Emma,

Patented Nov. 12,1929

u Nrr Eo STATLES PATENT OFFICE T m. nonr, or ELIZABETH, new 'J'EBSEY, assrenoa 'ro srmm on.

DEVELOPPIENT COMPANY, JACOBPOBATION OF DELAWARE 1' 'au'rouarrc summon on nnrnux m rmcrronn'rme 'rownns Application filed September 21,1925. Serial No. 57,606.

The present invention is directed to the art controlled and regulated. The invention will I eating ing a liquid and a vapor,

be fully understood by reference to the fol-- lowing description and accompanying drawin s, 1n which ig. 1 shows diagrammatically in sectlon one arrangement of parts required for prac ticing the invention; and

Fig. 2 shows an alternative arrangement of parts.

Referring tothe drawings, a bubble tower 1 or other equivalent vapor rectifying means, such as a dephlegmator, rectifying column, and the like, having plates2 or other devices equipped with means for intimately contactis positioned over a still or other vaporizing means (not shown) and receives vapors therefrom. Communi-- with the tower by means of a. vapor outlet 3, provided with a suitable deflecting plate 18 positioned to prevent substantial return of reflux to the tower, is a reflux or partial condenser 4 having an inlet 5 and an outlet 6 with connecting pipes or sections 15 through which there is passed a cooling liquid, preferably the stock to be fed to the still. A vapor line 7 connects the partial con-. denser to a final condenser (not shown). The vapor space of the partial condenser may be baffled or otherwise constructed to cause the vapors passing therethrough to follow a tortuous path while contacting with the cooled surfaces.

The partial condenser employed is pref erably somewhat oversize for serving simply as a reflux condenser and ordinarily produces more reflux than is necessary for the fractionation and rectification of the vapors produced. The excess reflux, the quantity of which is determined by the amount of reflux required for temperature control of the tower, flows out through a total reflux line 8 connected with an excess reflux line 9 by a section 14. Through this line 9 all excess condensate produced in the partial condenser is withdrawn and may be flowed into a separate cooler, passed to the finalcondenser for overhead vapors, or flowed to any other portion of the systemas desired. The total reflux line 8 is provided with a trap or liquid seal and is branched and extended as shown by a portion 10 controlled by a valve 11 and joined to a section delivering to the tower preferably at a positlon somewhat above the topmost plate therein. The valve 11 is automatically operated, preferably by compressed air or l1qu1d, by means of a thermostatic element 12 Wh1Cl1'1 S connected to the valve 11 by a line 19. Operation of the valve 11, therefore, causes a controlled but varying proportion of condensate to return to the tower through line 13 as the temperature of the vapors passing through the outlet, of the tower tends re-' spectively to rise or fall.

The condensate which is returned to the tower through line 13 as described, cools the vapors in the tower by vaporizing therein. As the temperature of the vapors inthe vapor outlet from the tower rises, the valve 11 is automatically opened and a larger portion of the total reflux is diverted through lines 10 and 13 into the tower, thereby cooling the upper portion thereof and restoring normal operating conditionstherein. In this manner an accurate control over the temperature the quality of distillate produced is maintained. The thermostatic element 12 and the setting of the valve 11 are adjusted so that while the proper reflux ratio and optimum operating conditions are in effect, a certain amount of reflux is returned to the .of the tower and consequently a control of tower while the remainder of the reflux is being overflowed through excess reflux line 9 and conducted to the condenser. As the temperature of the vapors within the tower tends to fall, the valve 11 will tend to close,

' thereby restricting the amount of reflux reis a collectindg steam be required therein. Uniform gravity of a stream of condensate is realized by means of the automatic control on the quantity of reflux returned to the tower in the manner as shown. With the valve 11 open a flow of liquid through pipes 8, 10, and'13 is caused, due to the esser height of the section 1( as compared with section 14.

An alternative arrangement of apparatus is illustrated in Fig. 2. As shown 1n this figure-a partial condenser 4 is positioned a ve the top plate 2 of the .tower 1. Between the partial condenser 4' and the top plate 2 pan 16 of suificient size and so positione as to collect the liquid condensed by the artial condenser 4. This con-v densate or re ux liquid is withdrawn from the tower through pipe 17 and is used lar e- 1y as reflux in the tower. The excess re ux thereby may be flowed through line 9 to the final condenser or otherwise treated. If the temperature of the vapors in the tower inadverteiltly tends to ecome too high for the operating conditions, the partially opened valve 11 is. further opened automatically by means of the thermostatic or heat responsive element 12, or by other analogous means. A suflicient quantity of reflux is returned to the tower through line 13 torestore normal operatin conditions therein. If the temperature 0 the vapors tends to become too low within the tower, the valve 11 closes somewhat, thereby slightly diminishing the amount of reflux returning to the tower and increasing the pro-1 portion of reflux overflowing through line 9.

It is apparent that the relative positions of the various parts of the apparatus may be varied somewhat if desired. For example,

by the temperature of condensate, a reflux line from said source to the tower, and automatic means actuated Q the vapors for directly controllingthe return to the tower of a controlled portion of the condensate so formed.

2. An ap aratus for rectifying vapors comprising t e combination of a tower, coolin means in conjunction with said tower, a re ux line for removing the condensate produced by saidcoolin means, a branch pipe leading from said re ux line to said tower, a valve in said branch pipe, and a heat responsive element in the vapor outlet from said tower whereby said valve is operated automaticall to control the amount of condensate returne to the tower.

3. An apparatus for rectifying vapors comprising the combination of a tower, a partial condenser adapted to condense the condensible vapors from said tower, a va or outlet beyond said partial condenser, a ine anterior to said partial condenser and connected to a liquid trap, an overflow line leading from said trap, a line from said trap to the tower, a valve in said line, and means for automatically operating said valve.

' HENRY M. 'NOEL.

the thermostatic element shown in Fig. 1 as positioned in the vapor outlet from the tower may be located in the vapor outlet from the partial condenser, or the element 12 shown in ig. 2 may be located below pan 16. A small by-pass line may also be provided around the control valve in order that acertain amount of reflux able and continuously supplied to the tower. The control valve 11 is preferably partly opened in normal operation and automatically closed to a definite extent as the temperature in the tower tends to fall, or is opened to a sli ht-ly greater degree as the temperature wi the tower tends to rise. Furthermore, it is also within the scope of my invention to replace the partial condenser shown with a total condenser and then to return the quantity of condensate necessary for controlling the temperature of the vapors within the tower by pump means, if esired, or by gravity flow means as shown.

claim:

1. An apparatus for rectifying vapors comprising the combination of a tower, cooling means for condensing a portion of the outmay be constantly avail- I 

